I. Field of the Invention
The present invention relates generally to heating systems and, more particularly, to a high efficiency furnace construction for a forced air heating system.
II. Description of the Prior Art
There are many previously-known forced air furnaces for home use or the like. These previously-known forced air furnaces typically use natural gas or fuel oil for the heating medium. The combustion of the natural gas or fuel oil heats a plenum above the furnace while the exhaust fumes resulting from the combustion are exhausted through an appropriate flue.
A disadvantage of these previously-known heating systems is that a substantial portion of the hot combustion fumes exhaust through the flue and exteriorly of the home. The exhaustion of hot exhaust gases from the furnace, of course, results in a heat loss from the furnace and unnecessarily reduces the heating efficiency of the furnace.
Yet another disadvantage of these previously-known heating systems is that, as previously mentioned, such systems are typically restricted to the use of fuel oil or natural gas as the heating medium. The price of both natural gas and fuel oil has rapidly increased in recent years and it is expected by many that the increase in price of these fuels will continue to rapidly increase in the future. Moreover, many expect these so-called fossil fuels to become completely depleted and unavailable in the not distant future.
The reliance of these previously-known furnaces on natural gas and fuel oil presents still a further problem, namely that these fuels are not currently available to the more rural areas, not only of this nation, but of the world. Even in the rural areas where these fossil fuels are available, the cost of transporting these fuels into those areas is excessive.
While there have, of course, been previous furnaces suitable for burning wood, these have generally been quite inefficient.